Cardiac and Pulmonary Care in DMD

Video content above is prompted by the following: Current care consensus guidelines recommend initial cardiology assessment at the time of Duchenne muscular dystrophy (DMD) diagnosis, regardless of age, with baseline echocardiogram and electrocardiogram testing. Cardiac MRI consideration typically begins around age 10, though some centers are implementing earlier screening protocols. The critical principle in cardiac care is proactive rather than reactive management, initiating cardioprotective medications before significant decline occurs, as interventions are less effective once substantial cardiac damage has developed. Pulmonary function follows a similar trajectory to motor function, with peak capacity typically occurring between the ages of 8 and 10, followed by decline averaging 4% to 5% annually in forced vital capacity among steroid-treated patients. Pulmonary function testing limitations include the need for patient cooperation (typically achievable around age 6) and inability to test patients with severe autism or anxiety. Proactive respiratory management includes breath stacking exercises, cough assist devices initially used during illness, and eventually daily respiratory maintenance routines. Sleep studies become increasingly important as pulmonary weakness progresses, identifying hypoventilation that compromises sleep quality and places additional cardiac stress. Steroid-related weight gain can cause obstructive sleep apnea requiring continuous positive airway pressure therapy before the more traditional bilevel positive airway pressure support needed for neuromuscular weakness. Both cardiac and pulmonary care require specialists experienced with DMD, as emerging therapies are modifying traditional disease phenotypes, creating uncertainty about optimal intervention timing and the potential consideration of previously uncommon treatments like cardiac transplantation in advanced disease stages.